As part of a Surveyor's inspection related
to the mortgage valuation and / or Homebuyer's survey, they
will check for dampness using an electrical conductance moisture
meter most commonly manufactured by "Protimeter".
Dampness is one of the three most common
defects found in domestic properties.
The electrical moisture meter can only
be used to accurately assess the level of moisture in timber.
This was the task it was designed for! When used in other
materials it can only record the presence of surface moisture
and is unable to determine the true moisture content existing
below the surface, i.e. within the wall.
Surface moisture can often occur in the
base of external walls during the winter months especially
if they are of solid construction (i.e. without a cavity).
The Surveyor is therefore only able to
detect surface moisture and will often report: "there
is evidence of dampness and remedial damp=proofing work in
this respect is required". Alternatively: "that
a specialist contractor on rising damp and timber defects
be instructed to inspect and to carry out their recommendations
The purchaser may then proceed to commission
specialist remedial treatment contractors either selected
from say, "Yellow Pages" or perhaps recommended
by the Estate Agent to inspect and provide a report and
These contractors, who normally offer
a free survey, also use electrical moisture meters and they
are likely to report: "Random tests were carried out
with a moisture meter to both internal and external wall at
ground level. At the time of our inspection, high levels of
dampness were obtained in the following areas... It is our
opinion that these high levels of dampness found at the base
of the aforementioned walls are attributed to rising dampness
due to the absence of an effective damp proof course.
They would then recommend installation
of an injected replacement damp proof course and associated
internal re-plastering. This work would substantially disturb
the existing internal decorations.
The contractors quote for the work they
propose might conceivably total £2000. In addition, the mortgage
lender may hold back a retention until the work the Contractor
recommends is completed !
Obviously, the contractor's opinion that
rising damp exists, has not been substantiated by any in-depth
testing as recommended within Building Research Digest 245
"Rising Damp in Walls - diagnosis and treatment".
Additionally, it should be borne in mind
that they have a vested commercial interest in recommending
work that they would undertake.
For impartial and accurate professional
diagnosis of alleged dampness, you may wish to contact us.